Mental stress-induced silent myocardial ischemia detected during ambulatory ventricular function monitoring.

BACKGROUND: Transient ischemic episodes at rest in patients with coronary artery disease have been attributed to mental stress. The means to monitor and record cardiac function changes due to mental stress is now available by utilizing the nuclear VEST. METHODS AND RESULTS: Eight, patients with angiographically documented coronary artery disease and 8 normal volunteers underwent a 4 hour session of continuous monitoring and recording of the left ventricular function, electrocardiogram, and blood pressure during exercise and mental stress. In the normal group, all subjects showed the expected normal response to exercise with an increase in ejection fraction, heart rate and blood pressure. During mental stress two subjects (25%) showed transient episodes of ejection fraction decrease that were not associated with chest pain, ST changes or significant changes in blood pressure. In the group of coronary artery disease patients, five (63%) had an ischemic response to exercise by electrocardiographic and radionuclide ventriculography criteria with evidence of chest pain in three of them. All of them revealed transient episodes of left ventricular dysfunction during mental stress. Episodes were painless, occurred at low heart rate and in most cases were accompanied by ST-segment changes. The rest of the patients with a normal response to exercise showed slight changes of the ejection fraction above the baseline. CONCLUSION: The results provide evidence that there is marked disparity in the incidence of chest pain and ST-segment changes, despite similar ischemic ejection fraction response between mental and physical stress. This is indicative of a major role of mental stress in provoking silent ischemia that potentially might provide additional clinical information compared to exercise test.

Detection of silent left ventricular dysfunction during daily activities in coronary artery disease patients by the nuclear VEST.

Myocardial ischemia during routine daily activities was studied in patients with known coronary artery disease with an ambulatory radionuclide probe and recording device (VEST) and routine rest and exercise gated blood pool imaging. Seventeen patients were monitored for 60 minutes while sitting (baseline), standing in place, walking, eating (6 patients), and urinating (4 patients). Eleven of them (64%) failed to show an augmentation of at least 5% in the LVEF on an exercise gated blood pool imaging study (Group I) and 6 (36%) showed a normal response (Group II). Three patients (18%) in Group I experienced angina. Transient left ventricular dysfunction was detected by the VEST during walking, urinating or eating in 80% of the patients in Group I and 33% in Group II (p < 0.05). During walking, mean ejection fraction slightly decreased from 45 +/- 12% to 43 +/- 13% in Group I while the ejection fraction increased from 46 +/- 8% to 51 +/- 12% in Group II (p = 0.04 for the difference in responses). Standing in place and eating did not affect the mean ejection fraction. Urination in 4 patients in Group I caused a significant drop in ejection fraction in 3 patients for a mean change from 51 +/- 9% at rest to 42 +/- 15%. By contrast, none of the patients had angina or diagnostic ECG changes during the monitoring period.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise-induced myocardial dysfunction in patients with coronary artery disease with and without angina.

Left ventricular dysfunction during exercise is considered a relatively sensitive marker of ischemia in patients with coronary artery disease. The purpose of this study was to determine whether exercise-induced myocardial dysfunction was more severe in patients with angina than in patients with ischemia without angina. Seventy-seven patients with angiographically documented coronary artery disease and an abnormal left ventricular response to exercise were studied by means of gated blood pool imaging. The arteriographic and functional parameters of 24 patients with angina during exercise testing imaging. The arteriographic and functional parameters of 24 patients with angina during exercise testing were compared with those of 53 patients who were pain free at the time of the test. Both groups were similar with regard to rate of multivessel disease (50% vs 51%, p = NS) and prior myocardial infarction (46% vs 51%, p = NS), as well as age, sex, and history of angina. Mean global ejection fraction remained unchanged (but abnormal) in both groups of patients during exercise. Furthermore, evidence of new regional asynergy during exercise assessed by a five-point scoring system was found to be equally abnormal in the two groups. Results of this study suggest that the severity of exercise-induced global and regional left ventricular dysfunction is independent of the presence of absence of angina during exercise testing.